People who are sad or depressed really do avoid eye contact, according to new research by a psychologist at Anglia Ruskin University.

Dr Peter Hills, Lecturer in Psychology at Anglia Ruskin, carried out experiments to discover how mood affects the way individuals look at other people.

The research - co-authored by Dr Michael Lewis of Cardiff University - is published in the latest edition of the British Journal of Psychology and shows that happy people are more likely to detect changes in eyes than participants who are unhappy.

"Depressed people tend to avoid eye-contact in social situations and in experimental settings, whereas happy people actively seek eye-contact," said Dr Hills, who also discovered that, conversely, sad people more accurately noticed 'external' changes such as hairstyle.

One suggestion Dr Hills has proposed is that avoiding eye contact may actually increase depression amongst already unhappy individuals, as it can lead to isolation.

"Sad people avoiding eye contact will disrupt normal social fluency and may lead to them shunning certain social situations," said Dr Hills. "Although this may reduceanxiety caused by the situation itself, it may actually increase social isolation and deepen their already sad mood."

"An alternative perspective on our findings is that rather than sad-induced participants avoiding the eyes, they process faces based on the external features, such as hair, rather than the internal features. Internal features, which include the eyes and nose, are those most commonly used to recognize familiar faces.

"Thus, sad-induced participants may treat all faces in the same way, as if they were all unfamiliar, which again may increase the risk of social isolation."

Dr Hills and Dr Lewis constructed 12 "prototype faces" using a computer-based face-reconstruction system. The software allowed a set of features to be selected, such as head shape, hairstyle, eyes, eyebrows, nose, mouth, and chin shape. These features were then enlarged, shrunk, or moved in relation to the other features.

To induce mood, participants performed an autobiographical memory task while listening to specific pieces of music, which were selected having been tested on psychology undergraduates in a previous study.

Mozart's Requiem was played to induce a sad condition, The A-Team music for a happy condition, and the theme from The Hunt for Red October for a neutral condition.